A Virtual Tour Through The Dredging Experience In Damen Nieuws

Head line of the virtual tour through the Damen Dredging Experience in Damen Nieuws

One of the things I like about my work is to tell people about it and explain all the delicate details of dredging in a fashion that everybody should be able to comprehend the complexity of moving sand. I am very fortunate to work at Damen as they gave me my own museum to care for: The Damen Dredging Experience1. I’ve discussed several of the exhibits in the Experience on this website already2. Since our last appearance in the internal Damen Nieuws magazine3, the intriguing science of dredging caught the attention of the editorial board. And what better way to share our knowledge on dredging than reporting about it in our Damen Nieuws.

Here on my own website, I already introduced ‘the Experience’ about two years ago, intending to cover the various exhibits regularly. Alas, reality not always behaves as planned. There were so many other interesting items to share, or current CEDA events, or urgent requests from the service department. Well, this publication is a good incentive to continue my coverage of the Damen Dredging Experience.

First exhibit in the entrance hall: a real size DOP pump
First exhibit in the entrance hall: a real size DOP pump (Credit: Judith Korver)

One part of the experience, that does not lend itself for a very detailed explanation is the entrance to the building and the journey to the fourth floor where the experience is located. Immediately after entering the building, you may be overwhelmed by the DOP pump suspended from the ceiling. DOP pumps by themselves are not very large. But, when they are displayed out of place like inside a building, they are still formidable machines. Visitors can be introduced to the general composition of our dredging equipment with this DOP pump: it is basically a small scale dredging machine. It has a suction mouth, a dredge pump and a construction to keep everything together. Same follows for a CSD or even a hopper dredge.

Pictures about the history of The Netherlands and dredging used in the wall illustrations
Pictures about the history of The Netherlands and dredging used in the wall illustrations

Next are four floors with murals depicting topics from the dredging industry. First floor is covering the history of dredging in the Netherlands. How we always had to battle the sea to keep our land dry and tame the rivers for infrastructure. This long history made The Netherlands an excellent breeding ground for knowledge on dredging. The blooming industry is backed up by centers of excellence as the TU Delft, Marin and Deltares. With each of which we as Damen have cooperated to develop our products.

Pictures about the historical relation between Damen and dredging on the second floor
Pictures about the historical relation between Damen and dredging on the second floor

Within the Dutch dredging industry Kommer Damen played a pivotal role in the supply of auxiliary equipment to the big dredging contractors. Eventually, the company De Groot Nijkerk was acquired to also deliver dredging equipment directly.

Pictures with Damen products used in projects around the world
Pictures with Damen products used in projects around the world

Our products have been applied world wide on small and large projects. Everywhere where some wet infrastructure was developed, Damen has supplied some or more equipment. It always makes me proud to see the result of a big project and know that in some (remote indirect) way I have contributed to it.

Pictures illustrating the future of dredging industry
Pictures illustrating the future of dredging industry

The last mural is about the future of the dredging industry. One example is the increasing demand of raw materials. Beginning with the most basic of all: sand for the concrete industry. Increasingly, we see more demand for more exotic materials that are even harder to get: sea floor minerals from the abyss of the ocean. The other example is the ever increasing environmental awareness of society and the attention of cleaning up contamination and creating value for nature. Each of which our DOP pumps form the beginning is excellently purposed.

The Damen Dredging Experience is available for anyone who wants to visit, although it is best to request an appointment with one of our staff4.

Overview of the exhibits in the ‘Damen Dredging Experience’
Overview of the exhibits in the ‘Damen Dredging Experience’

References

  1. Damen Dredging Equipment in Nijkerk Officially Open, DredgingToday
  2. Dredging Experience, Discover Dredging
  3. Our Interview About New Pump Designs In The Latest Damen Nieuws
  4. Contact, Damen Dredging Equipment

See also

How A Ship On The Shore Became a Beacon For My Dredging Career

Stranded Yo, us and another vessel to the rescue (Credit: Co Winkelman)
Stranded Yo, us and another vessel to the rescue (Credit: Co Winkelman)

Long ago, we were sailing with my parents and my brother into the Venezuelan archipelago of ‘Los Roques’.1 After clearing customs, we learned that there was another sailing vessel in trouble. It was stranded on the reefs at the east side of the islands. As we had some spare time we decided to lend a hand in getting them afloat. By eyeball navigation through the channel behind the coral reef, we found the stranded English catamaran ‘Yo’, but had to anchor 200m away. First we learned from a Swiss captain on another assisting yacht they had been pulling together with a maxi yacht on a long hawser to pull them off by power and sail. Alas, to no avail.

Location and map of the islands of Los Roques
Location and map of the islands of Los Roques

The next day, the swiss captain had to leave and we undertook the journey by dinghy to visit the crew on ‘Yo’. It turned out to be a couple with their son and two deckhands. They told us that the maxi yacht was ‘Drum’2 and one of the crew was no other than rock star Simon Le Bon3 himself. We just missed them by a day! He did all the best to cheer them up and you can image what a support that visit meant to these people in such a desperate situation.

Salvage plan to float ‘Yo’
Salvage plan to float ‘Yo’

As my dad was a chief engineer from the merchant marine, he surveyed the damage professionally. ‘Yo’ was sitting exactly on top of the reef. One keel was broken of and the other only half, but was sheared below the wreck and stuck between the coral heads, preventing any movement. After evaluating the state of the boat, the equipment and the location, he actually said: ‘We’re gonna science the shit out of this.’4 Together we devised a cunning plan:

  1. Lift/Float: Remove the rest of the keel. Plug the holes left by the bolts and increase buoyancy of the craft.
  2. Dredge: Lower the rock bottom to increase support from the buoyancy and create a channel to freedom.
  3. Move: Assemble all winches and tackle to leverage the pulling forces. The forces would be so high that we feared we would pull the catamaran in half. So we had to distribute the forces all around the hull.

The structural repairs on the hull were performed by my father. My brother and me were in charge of the winches and tackle. Any spare time was dedicated to cutting the rock below the wreck. For sure, that is a nasty job, we tore our clothes and cut ourselves on the sharp edges of the coral. By practice, I learned the different angles to aim the pickaxe for the best results and the lowest effort: an introduction into Specific Cutting Energy!5 Because we did our calculations careful and our assumptions were right, the boat moved exactly the moment we predicted and in the way we wanted. It was a great moment of revelation: you could actually use all this knowledge from physics classes6 to get you out of a nasty position. It set me on a path where I am now and you are reading this story.

The best home schooling: toolbox meeting for a salvage operation. (Credit: Co Winkelman)
The best home schooling: toolbox meeting for a salvage operation. (Credit: Co Winkelman)

Actually, we did not see them completely get off, as we had other obligations and had to leave. We were confident they would come off, but it was a mystery to us where they did end up. Finally after thirty years, I did a Google search and to my surprise I found they did get off indeed and were even reunited with their first rescuer, Simon Le Bon.7

‘Yo’ is away, but still scars are left behind in the coral where it all happened. (Credit: Google)
‘Yo’ is away, but still scars are left behind in the coral where it all happened. (Credit: Google)

That was my own story on dredging and salvage. Currently, there is an interesting exhibition at the National Dredging Museum8 with better documented cases and very interesting displays. Still, the three steps used for ‘Yo’: ‘Lift, Dredge and Move’ can be distinguished for the other cases there, also.

Exhibit of the salvage operation of the ‘Faustus’ from the Rotterdam breakwater
Exhibit of the salvage operation of the ‘Faustus’ from the Rotterdam breakwater

Remarks

Please keep in mind, that these events happened more than thirty years ago and were about saving the lives of five people in immediate danger. Dredging in coral should only be done under very strict conditions with the health of the ecosystem in the first place and in balance with the necessity of the operation.

References

  1. Los Roques archipelago, Wikipedia
  2. Drum (yacht), Wikipedia
  3. Simon Le Bon, Wikipedia
  4. The Martian: Mark Watney Quotes, IMDb
  5. Experiencing The Cutting Edge Of Dredging Technology, Discover Dredging
  6. BINAS, Noordhof
  7. Rescued woman reunited with pop star, BBC
  8. Scheepswrakken bergen of baggeren? National Dredging Museum

See also

Graduation Omar Karam: Rock Cutting The Egyptian Way

Graduation presentation of Omar Karam
Graduation presentation of Omar Karam

Egypt is a great nation when it comes to ancient engineering. No other country has such a concentration of impressive monuments and such an interesting history as over there. If you are not convinced that modern Egyptians are not capable of great engineering feats you are wrong. Last Monday, Omar Karam graduated at our R&D department of Damen Dredging Equipment1 on his thesis about ‘CSD Rock Cutting.’

Cutting processes have been extensively described by Sape Miedema in ‘The Delft Sand, Clay & Rock Cutting Model’2. Omar has been using the frame work of Miedema to make some useful tools for the estimation of the production of our dredging equipment in rock. In due time, you will find the results of his thesis in the online dredge selection tool ‘Sandy’. Omar’s curiosity and ingenuity does not end here. He will continue studying at a university, but I do hope to meet him again, as he would be a valuable asset for our dredging community. Keep an eye out for him.

Program structure diagram of cutting force calculations
Program structure diagram of cutting force calculations

His graduation brings me back to my first lessons in dredging technology at the Delft University of Technology by the illustrious professor de Koning. In a sense he was an old school engineer, who hammered it in to us that thinking is done by doing it with your hands3. Back than the Polytechnic School was just rebranded to University and he was mocking that as a university, we had to set the topics in a broader perspective. So, he started his introduction on cutting technology with some slides of the unfinished obelisk at Aswan4 as every aspect of the cutting process could be illustrated.

Phases of chip forming in rock cutting
Phases of chip forming in rock cutting

The story according to de Koning is: ‘Around the quarry of the obelisk, they have found diorites5. These are some sort of volcanic balls of rock. In combination with the marks and scratches all around the obelisk, archaeologists believe these stones have been used to pound the granite. The impact compresses the bedrock and the resulting stresses fracture the contact surface(1). For every hit a whiff of dust is created. Eventually the dust is collected and scooped away for the next layer. Next, trees would be planted in the trench on one side of the obelisk. The growing root system displaces volume and create shear stress underneath the obelisk that would sever the obelisk from the bed rock(2). At last the trees are removed and dry wooden dowels would have been inserted in the shear cracks. Saturating the wooden dowels will make them grow. The last strands of rock will now be broken due to tensile stresses(3). Repeated insertion of new dry dowels and saturating them will lift the whole obelisk enough to pull some ropes under and carry the obelisk away to the building site.’

Although the diorites and the scratch marks are a smoking gun, current archaeologists argue about the feasibility of this process as experiments yield a very low production and it is doubted that the obelisk could be finished in the lifetime of the client6. Even if disputed, de Koning told a story that conveys the message; I vividly remember it and makes me understand the rock cutting process.

These mysterious monolithic ornamental spires have been an inspiration for many legends and stories. When we have solved the riddle of the rock cutting with diorite balls, it may inspire the development of new rock cutting technology for the dredging community and we can put the story of the obelisks to an end.7

End of the story on the cutting of obelisks (Credit: Uderzo)
End of the story on the cutting of obelisks (Credit: Uderzo)

References

  1. Innovation, Damen
  2. The Delft Sand, Clay & Rock Cutting Model, TU Delft
  3. De Koning (1978), Denken met de handen’, TU Delft
  4. Unfinished obelisk, Wikipedia
  5. Diorite, Wikipedia
  6. The Unfinished Obelisk, NOVA
  7. Asterix and Cleopatra, Goscinny-Uderzo

See also